A Multi-Segment SVM Scheme for the Capacitor Size Minimization in SiC Devices-based Active Neutral-Point-Clamped Converters

The active neutral-point-clamped (ANPC) topology is one of the most prominent converter choices for the low and medium voltage applications. However, lowering its dc-link capacitor values remains a challenge. This paper proposes a novel multi-segment space vector modulation (MS-SVM) scheme for the SiC devices-based active neutral-point-clamped (ANPC) converter to lower the dc-link capacitor size. In this paper, the selection of most optimal switching states is investigated to achieve balanced capacitor voltages. These states are then utilized to minimize the dc-link capacitor values using the proposed switching sequence of the MS-SVM scheme. The proposed MS-SVM scheme mitigates the third harmonic voltage ripples across the dc-link capacitors in ANPC converter, which results in lower requirement of dc-link capacitor value. A detailed analysis is presented to investigate the effect of proposed MS-SVM scheme on the dc-link capacitance. Further, the performance of proposed control scheme is compared with that of the existing scheme for various load current values. A scaled-down experimental prototype of the three-phase ANPC converter is constructed to validate the performance features of the proposed MS-SVM scheme. Finally, the key experimental results are presented to demonstrate the working principle of ANPC converter using MS-SVM scheme.